This specification pertains to what are termed herein as "display arrangements". More specifically it pertains to display arrangements which utilize thermochromic compounds and/or compositions to give or cause different visual effects.
The term "display arrangement" is employed in this specification to designate a composite structure or article which is intended to convey a visual expression or message. Thus, this term is employed to designate various types of advertising signs employing verbally expressed messages of one sort or another. It is also employed in this specification to designate various types of graphic displays which are intended to be viewed. Such graphic displays may consist of a pattern or a picture of one sort or another. From this it will be apparent that this term "display arrangement" is a rather broad term intended to designate a number of items of a utilitarian and/or an artistic nature.
The term "thermochromic" is employed in this specification to designate a characteristic or property of a material or composition causing such a material or composition to visually appear as being of one color at one temperature and another color at another temperature. At times other terms have been utilized to designate thermochromism. Thus, the expressions "thermotropically colored material" and "chromo-thermosensitive material" have on occasion been utilized in the appropriate technical literature in a manner which is synonymous with the manner in which the term or expression "thermochromic material" is used herein. A number of different types of thermochromic materials are known.
Some of such materials are referred to as reversible thermochromic materials as they will change from one color to another and then back again as they are heated and cooled. Other of such materials are irreversible in character in that they will only undergo a single color change on being heated or cooled. The color changes in such materials may be the result of relatively complex chemical considerations. They also may be the result of comparatively simple considerations such as, for example, the absorption of moisture from ambient air and/or the melting of one material into another.
An understanding of the subject matter of this specification does not require a detailed consideration of the nature of thermochromic materials and/or the mechanism used in obtaining thermochromism. The subject matter of this specification relates to the utilization of known thermochromic compounds and compositions in connection with various types of display arrangements so as to obtain changes in the appearances of such display arrangements which are visually stimulating and/or attractive from an aesthetic sense.
As an example of the desirability of using changes in appearance in display arrangements reference may be made to common advertising signs. Such a sign may be constructed so as to have a message and/or various appropriate ornamentations painted upon the sign using conventionally pigmented paint. Once created such a display arrangement will normally always look the same. While this is acceptable for many utilizations it has been established that a change in appearance of the sign will frequently make such a display arrangement more interesting to an observer and/or more apt to catch visual attention.
The recognition of the latter has, of course, led to the development of all sorts of changeable exhibitors, specialized lighting arrangements and the like which are intended to stimulate visual attraction. While expedients of these general types are unquestionably effective it is considered that in general they tend to be undesirable in many applications for one or more of a variety of different reasons, none of which are significant relative to an understanding of the nature of display arrangements as herein set forth.